Pressure Test - Stihl 034 Series User Manual

mounting screws. Push the narrow
end of the sealing plate home so
that it is just below the lower casing.
– Retighten the mounting screws
moderately.
– Remove the carburetor -
– Set the piston to top dead center
(T.D.C.). This can be checked
through the inlet port.
2
– Remove screw 1128 855 9000
from test flange 1128 850 4200.
Fit the test flange (1), number "1"
facing up and flat side first, on the
carburetor studs.
While fitting the test flange, make
sure the impulse opening on the
manifold flange is properly
sealed (see arrow).
Fit the two hexagon nuts (2) and
tighten them down moderately.
32
5.6.2

Pressure Test

– Preparations -
– Check tightness of spark plug
before starting leakage test.
– If decompression valve is fitted,
make sure it is tight and closed.
see 12.3
2
1
1
Connect pressure hose (1) of
tester 1106 850 2905 to nipple on
test flange (2).
Close the vent screw (1) on the
rubber bulb.
see 5.6.1. – Pump air into the crankcase with
rubber bulb until the gauge
indicates a pressure of 0.5 bar. If
this pressure remains constant
for at least 20 seconds, the
crankcase is airtight.
– However, if the pressure drops,
the leak must be located and the
faulty part replaced. Then repeat
the pressure test.
Note:
To find the leak, coat the suspect
area with oil and pressurize the
crankcase. Bubbles will appear if a
leak exists.
– Open the vent screw and
disconnect the hose.
– A pressure must always be
followed by a vacuum test -
5.6.3.
– After finishing the tests,
reassemble all parts in the
2
reverse sequence.
Note:
Coat the mounting screws for the
upper and lower muffler casings
with LOCTITE. Insert and tighten
down the screws (see "Tightening
Torques").
1
see
034, 036, 036 QS